This just in: all trace of Man as we know it could disappear from the Earth in 200,000 years.

IF MAN were to vanish from the face of the Earth today, his footprint on the planet would linger for the mere blink of an eye in geological terms.
Within hours, nature would begin to eradicate its impact. In 50,000 years all that would remain would be archaeological traces. Only radioactive materials and a few man-made chemical contaminants would last longer — an invisible legacy.